Conveying device



April 20, 1965 R. N. GUNZELMANN CONVEYING DEVICE 3 Shepts-Sheet- 1 Original Filed Sept. 18, 1958 N MM"? WW f w A ril 20, 1965 R. N. GUNZELMANN CONVEYING DEVICE 3 Sheets-Sheet. 2

Original Filed Sept. 18, 1958 flw 9 11 1 F .H LIJHRKIHHFFHWI/JL 2 4, w... 4 3 9 f 5 1 A W W 7 W. n w I lh pullwl u iufil fi m r w 1 m FIG. 2 w

April 1965 R. N. GUNZELMANN 3,179,460

CONVEYING DEVICE Original Filed Sept. 18, 1958 3 Sheets-Sheet 3 46 1344 1 FR 130 M. "ii/29 a5 K HMH/LNA 62 FIG. 3 V

United States Patent 3,179,460 CONVEYING DEVICE Rudolf N. Gunzelmann, Grobe Viereu 20, Bremen, Germany Original application Sept. 18, 1953, Ser. No. 761,908, now Patent No. 3,090,502, dated May 21, 1963. Divided and this application May 16, 1961, Ser. No. 114,275 Claims priority, application Germany, Nov. 9, 1957,

2 Claims. ci. 294-63) This invention relates to apparatus for the production of setting mouldings and is a division of application Serial No. 761,908, filed September 18, 1958, which has matured into Patent No. 3,090,502. Application Serial No. 761,908 was in turn a continuation-in-part of abandoned application Serial No. 472,497 filed on December 1, 1954, in the name of Rudolf Gunzelman for Method of and Apparatus for the Production of Setting Mouldings Particularly Lime Sand.

The invention has primarily for its object to provide certain improvements in such apparatus which result in improved operation whereby the possibility of damage to the bricks during transportation and stacking is reduced to a minimum if not entirely eliminated.

More particularly it isan object of the invention to provide an improved construction of gripper assembly and means for traversing the same between the take up position and stacking position which enables the operations of taking up bricks traversing and depositing for stacking to be carried out smoothly so that the bricks are not subjected to unnecessary loads which could result in damage thereto.

According to a further object, the invention provides a gripper arrangement which includes at least two gripper units each of which has two pairs of individual gripper plates so that the apparatus can be used to handle at least four bricks at a time.

It is a further object of the invention to provide a gripper arrangement having gripper plates all of which are mounted so as to be movable into and out of engagement with the bricks, such gripper plates being for preference capable of an initial movement under gravitational force into contact with the bricks and operable after such initial movement by operating means into positive engagement with the bricks, locking means also being provided to hold individual pairs of gripping plates separated whilst moving towards the position for taking up bricks.

A still further object of the invention is to provide a gripper arrangement wherein termination of the downward movement of the grippers results from engagement between stop means and a fixed surface, e.'g. the conveyor for green bricks, the mouldings themselves or the surface of the stacking platform.

A still further object of the invention is to provide a gripper arrangement wherein individual gripper plates are constituted by a plurality of resilient tongues or alternatively such plates are resiliently mounted, thesurfaces of the plates engageable with the bricks being if desired, provided with a covering of for example, sponge rubber or other resilient material.

In order that the invention may clearly be understood and carried into effect the same will now be described by aid of the accompanying drawings in which:

FIGURE 1 shows in elevation and to an enlarged scale a modified form of the gripper arrangement, a portion on the left side of this figure being a section on the line 1-1 of FIGURE 2.

FIGURE 2 is a sectional view on the line II-II of FIGURE 1 and FIGURE 3 is a sectional view on the line III-J11 of FIGURE 1.

3,179,4hh Patented Apr. 20, 1965 ice The method illustrated is particularly suitable for use in the production of hollow bricks in the lime sand brick industry, but may be used to advantage for the production of sensitive solid bricks as well.

The stacking device is constructed as described hereafter. The essential part of the stacking device is the gripper arrangement denoted generally by reference 19. In the embodiment shown in the drawings this gripper arrangement is provided for the simultaneous seizing of four mouldings 16 of hollow block bricks or of a corresponding number of mouldings of small bricks. These four mouldings are, however, not gripped by one pair of gripper plates, but on the contrary, a separate pair of gripper plates is provided for each individual moulding. The gripper plates can be moved vertically relative to their gripping surface.

The gripper arrangement shown in the drawings consists of two gripper units each of which incorporates two separate pairs of gripper plates, the said two pairs of plates in each unit being so arranged that a plate from each pair is operable by common operating means into positive gripping engagement with the bricks. Thus as shown in FIGURE 1 the gripper unit at the left of the drawing consists of the separate pairs of gripper plates 25, 27 and 26, 28, respectively. The two plates 25, 26 move initially by gravity into contact with the bricks and are then operable by a common operating means to grip the bricks. Similarly the plates 27, 28 move initially into contact with the bricks and by further common operating means into positive gripping engagement therewith, the said operating means being interconnected, so that the grippers operate in synchronisrn to grip each brick by opposite end faces.

The two gripper plates 25 and 26 are hinged at 108 and slightly spreadable relative to one another by a wedge 116 adapted to engage in a slot 107 formed between said plates as soon as the gripper arrangement commences upward movement, after having been lowered on a conveyor belt 11. The wedge 116 is the middle part of a U-shaped frame which is suspended from the upper yoke 42 by its vertical legs 109. For this purpose the upper end of each leg 109 has a bolt 110, the head of each bolt having a slot 111 in it, in each of which one end of pins is located. The pins 150 are arranged co-axially with one another the inner end of each pin being fastened to a with the right hand gripper unit (FIG. 1) is supported in a manner identical to that just described the connection to the upper yoke 42 being by tube 34.

By this suspension the wedge 116 is movable horizontally for the purpose of a good gripping function. Said four gripper plate assemblies act together with four rows of eachten movable gripper plates 27, 28, 29 and 30. As shown each gripper plate is constituted by a plurality of resilient tongues of for example spring steel, arranged side by side and secured by their upper ends to a rigid support. The surfaces of the tongues engageable with the bricks have a covering of resilient material. The gripper plates 27, 28 and 29, 30 are connected with levers 31 which in their turn are connected by means of levers 32 with said tubes 33 and34 movable in axial direction. The tubes 33 and 34 are slidable on bolts 35 and 36 respectively which are rigidly secured to a supporting bracket 41 of the gripper frame. The levers 31 carrying the movable gripper plates are pivotally mounted at 4 on said supporting bracket, whereas the spreadable gripper plates 25, 2a are articulated with said axes 108 114 to rods 43 and 44. These rods 43 and 44 are slidable in a vertical direction within the aforementioned tubes 33 and 34 and are slidable in upper bearings 45, 46. The rod 4-3 serves moreover for the operation of a limit switch (not shown) during the upward movement of the gripper arrangement. The gripper arrangement is suspended as a whole by means of a tube 4% the lower part of which is rigidly connected with the yoke 42. This tube 'is slidable in the vertical direction in a sliding hearing 49. A wire rope passing over a roller and operated by a winch drum (not shown) is connected to the upper end of the tube 43. The drum is driven through a suitable gearing by reversible motors and both for the upward and downward movement of the gripper arrang ment.

When the wire rope is moved upwards then the tubes 33 and 34 which are fastened to the yoke 42 and tube 4% slide upwards on the bolts 35 and 36, whereas the supporting bracket 41 remains stationary unless it is engaged by pawls 37. These pawls are formed by the ends of levers 57 each of which is pivotally mounted at 76 so as to be capable of a swinging movement. During the downward movement of the gripper to the conveyor belt each pawl catches in two slots 58 and 59 arranged approximately at the same height in the tubes 33 and 34 and in the bolts 35 and 36. The levers 57 act together with bolts 60 fitted to weighted levers and which strike against the levers 57 when the gripper descends towards the conveyor belt 11. During the downward movement of the gripper these weighted levers 38 are at first taken along with the levers 57. During this movement the weights 61 fitted to the lever are lifted because of the fact that the weight of the supporting bracket 4-1 With the gripper plates is suspended on the pawl 37 by means of the bolts 35 and 36. This weight retains therefore the pawl by means of friction so that the load of the weight 61 on the lever arm 38 is not in the position to withdraw the pawl 37 from the corresponding slots 58 and 59 of the tubes 33and 34.

In both embodiments the downward movement towards the conveyor belt is stopped when the gripper contacts the conveyor belt 11 itself. Supporting frame we are arranged in order to avoid damage of the resilient gripper plates when the gripper has descended onto the conveyor belt. These supporting frames 1% are secured to the supporting bracket .1 and may simultaneously act as guiding means for the wedges 1116 and their legs 169.

I Only when the gripper with its supporting frames 1'96 reaches the conveyor belt 11 then the pawls 37 are disengaged and consequently can be moved in the direction of arrow 115 by the weights 61 out of the slots 58 and 59 into the position as indicated in dotted lines in FIG. 2. During the first part of the upward movement of the grip per from the conveyor belt ill the supporting bracket 41 together with the gripper plates on it will not follow the upward movement of the gripper yoke 42 and the tubes 33 and 34, so that the wedges 116 which are fastened to the yoke 42 will enter the slots 1G7 and levers 32 will be pivoted about their joints 4. Thus the gripper plates are moved into positive gripping engagement with the mouldings on the conveyor belt. After having seized the mouldings the gripper plates are locked by the mouldings and thus prevent the further sliding of tubes 33, 34 on the bolts 35 and 36, so that the supporting bracket 41 is now carried along with tube 1% and yoke 42.

Bolts 140, 141 are fastened to the supporting bracket '41 the upper ends of the bolts projecting through yoke 42., adjustable nuts 142, 143 being provided at their upper ends. The nuts 142, 143 act as stops to limit the sliding movement of tubes 33, 34 on bolts 35 and 36, i.e. in case the gripper plates should not be locked by contact with the mouldings after withdrawal of pawls 37 from slots 58. t

The gripper arrangement 19 and its drive is supported by a carriage movable on rails 56 on a bridge arranged transversely to the conveyor belt ill.

ease

The vertical movementof the gripper is controlled by means of two. feelers 78 and '79. Each of these feelers consists of a pin 8% and 81 fitted with feet 82 and 83 respectively. These feet serve for contacting the conveyor belt it or the platform of a hardening truck or for contacting the layers of the mouldings already placed on the hardening truck. The pins 3%) and 81 are slidable in vertical direction in tubes 85 and 34 rigidly connected with the supporting bracket These pins have adjustable heads 86 and 87. The pin 3d is longer than the pin 81 and the heads 86, 37 are adjusted in such a manner that when the gripper is making a downward movement the foot 82 of the pin 8%} advances the foot 83 of the pin 81 by the thickness of a moulding. The heads 86 and 87 are fitted with rods 88 and 89. The lower ends of these rods act upon operating levers @ti and 91 of limit switches 92 and 93 for a motor (not shown). The electric connections are made in such a manner that by operating the switch $2 or 93 the motor for normal speed for the downward movement is disconnected and in place of this motor another motor (not shown) for reduced speed for the downward movement is connected. I

Completion of the upward movement of the gripper from the conveyor belt 11 is effected through the rod 43 by operation of a limit switch (not shown). Electric connections are made in such a manner that when actuating another limit switch (not shown) for the termination of the horizontal movement of a gripper carriage, the motor 53 for the downward movement of the gripper is started. The speed of the downward movement of the gripper towards the platform of the hardening truck or towards the stack of mouldigns on this truck is reduced by the feeler '78 or 791and the downward movement of the gripper is changed into an upward movement by means of the switch (not shown) in one embodiment of the invention buffers (not shown) with rubber cushions (not shown) are fastened to the bracket 41, said cushions contacting the upper side of the mouldings lid and thus stopping further downward movement of bracket d1, when the gripper is moved downwards in direction to the mouldings stacked on the hardening truck, because in this case the frame 1% cannot contact either the platform or the mouldings thereon.

FIGS. 1, 2 and 3 show a preferred arrangement for controlling the downward movement of the gripper towards the truck or a stack of mouldings on the truck. In this arrangement the downward movement is not interrupted as a result of contact between the gripper and platform or mouldings on the platform, but is effected by operation of a braking device which is operable in such a manner that the gripper movement is stopped before contacting the platform or the mouldings on it. I

This has the advantage that possible damage to the stacked mouldings is prevented.

For this purpose a braking device 1117 is provided, to which rods 43 and 44 of the gripper are connected through a free wheeling device 138 located adjacent the bearing 49. The rods 43 and 44 are connected to the device 138 by gear wheels 119 fixed on a shaft 12d rotatably mounted in bearings 136, 137, the gear wheel teeth being in contant engagement with rack teeth 121 provided-on each said rod 43 and 44.

The braking device 1317 consists of two main parts 122, 123 coaxially arranged on shaft 129, part 122 being fixed on the shaft whereas part 123 is mounted rotatably on shaft 12c and fixed nonrotatably in space by an arm 12.4 extending to bolt 118. Parts 122 and 123 are interconnected by a disc clutch 125 which is actuated by an electromagnet 12d. Switchers 127, 128 are provided for actuating electromagnet 126 as soon as feeler 82 or 83 has reached a predetermined limit of travel which is determined by a further downward movement of the gripper equivalent to the thickness of not quite one moulding. Upon upward movement of the gripper head 86 or 87 of pin St? or 81 will lift a pin 129 or we out'of contact with switch operating lever 131 or 132 of switch 127 or 128. For this purpose pins 80 and 81 are provided with longitudinally adjustable buffers 133 and 134 respectively. Switches 92, 93 and 127, 128 are mounted to a wall 135 which is carried by the supporting bracket 41.

After actuating electromagnet 126, the downward movement of rods 43 and 44 and supporting bracket 41 is stopped at, for instance, one or two millimeters distance between the mouldings Within the gripper and the platform of a hardening truck or the mouldings already stacked on this platform in the foregoing working periods of the stacking device. Then, on further downward movement of the tube 48 and yoke 42, tubes 33 and 34 will slide down on bolts 35 and 36 and wedges 116 will disengage from slots 107 so that gripper plates 25 and 26 are withdrawn by springs 139. Simultaneously levers 32 and 31 and gripper plates 27 to 30 are operated so that the mouldings are released by the gripper and drop said one or two millimetres onto the platform or onto mouldings previously stacked on the platform. Also the pawls 37 engage the slots 58 of tubes 33 and 34 again, and switch 94 is operated to reverse a motor to cause upward movement of the gripper arrangement.

The entire operation of a typical brick stacking device embodying this invention consists of the following six action cycles:

(1) Lowering of grippers 19 above the point where the green bricks 16 are seized.

(2) Lifting grippers above the point where the green bricks are seized.

(3) Horizontal transport of grippers to the point where the green bricks are stacked.

(4) Lowering grippers above the point where the green bricks are stacked.

(5 Lifting grippers above the stacking point, and

(6) Returning grippers to the point where the green bricks are seized.

During the downward movement of the gripper the levers 57 contact stop bolts and this effects a lifting of the weight 61 until the frames 106 of the gripper 19 contact the conveyor belt 11. At this time the pawl 57 is engaged by the weight 61 so that the tubes 33 and 34 with the yoke 42 are released. Upon release of strain on the rope a switch is simultaneously actuated and the sense of rotation of the motor is reversed whereby the change from the downward movement to the upward movement is effected.

When the gripper is raised the tubes 33 and 34 and the Wedge 116 are also raised whereas the gripper plates remain at first on the conveyor belt. This results in the plates 25 and 26 being spread by engagement of the slot 107 by the wedge 116 and also as a result of displacement of tubes 33 and 34 on the bolts 35 and 36. By means of the levers 31 and 32 the horizontal closing operation of the gripper plates 27 to 30 is effected so that the mouldings 16 are seized by the pairs of gripper plates. As soon as this horizontal movement of the gripper plates is complete and as soon as the mouldings 16 are held, a rigid coupling is made between the tubes 33, 34, the yoke 42 and the supporting bracket 41 and the gripper makes an upward movement together with the mouldings. The pawls 57 cannot now enter into the slots 58 of the tubes 33, 34 and remain outside of the tubes above the slots 58. This prevents engagement of the pawls when the gripper is moving upwards.

The lowering operation after horizontal transport proceeds in a similar manner to that eifected over the conveyor where the green bricks are seized. The only difference is that after the actuation by feeler 78 or 79 which converts from rapid lowering speed to slow speed, switch 127 is actuated shortly before the gripper with the green bricks reaching the stacking position of a truck or a stack of green bricks thereon and retains the gripper by a braking device 117. Thus when the grippers open the green bricks fall a short distance of about 1 mm. out of the gripping jaws and as the gripper arrangement is supported it does not rest on the stack of green bricks. The braking device 117 with electromagnet 126 can only be operated when the gripper is over the stacking point.

I claim:

1. A conveying device comprising a plate, a bracket disposed below and substantially parallel to the plate, a sleeve secured to and movable with the plate and eX- tending downwardly toward the bracket, a rod disposed within the sleeve and with its lower end secured to the bracket, said sleeve being movable on the rod, a pair of adjacent gripper plates carried by and extending downwardly from the bracket, gripping means formed on the outer faces of the gripper plates, a second pair of gripper plates with one facing each of the first pair of gripper plates, said second pair of gripper plates being carried by the bracket and linked to the sleeve by a lever system, a wedge disposed between the first pair of gripper plates and carried by the sleeve, said wedge spreading the first pair of gripper plates causing them tb move closer to the second pair of gripper plates in response to upward movement of the sleeve on the rod, means secured to the plate for raising and lowering the plate and the sleeve relative to the rod, and means for locking the rod and sleeve together and means including a feeler depending downwardly from the lowermost portion of said gripping plates for preventing the bracket and grippers from engaging the article to be conveyed by the device and a surface lying below said articles.

2. A conveying device comprising a plate, a bracket disposed below and substantially parallel to the plate, a sleeve secured to and movable with the plate and extending downwardly toward the bracket, a rod disposed within the sleeve and with its lower end secured to the bracket, said sleeve being movable on the rod, a pair of back to back grippers disposed in generally vertical planes and pivotally supported on a common axle carried by the bracket, a second pair of gripper plates with one facing each of the first pair of gripper plates, said second pair of gripper plates being carried by the bracket and linked to the sleeve by a lever system, a wedge disposed between the firstpair of gripper plates, a pair of arms extending outwardly from the sleeve beyond the axle and carrying the wedge between the first pair of gripper plates, said wedge pivotally separating the first pair of gripper plates causing them to move closer to the second pair in response to upward movement of the sleeve on the rod, means secured to the plate for raising and lowering the plate and sleeve relative to the rod, means for locking the rod and sleeve together means including a feeler secured to the plate for preventing the plate and grippers from engaging articles to be conveyed and a surface lying below said articles.

References Cited in the file of this patent UNITED STATES PATENTS 1,710,096 Luce Apr. 23, 1929 2,668,731 Neher Feb. 9, 1954 2,710,696 Fontaine et al June 14, 1955 2,822,094 Greer Feb. 4, 1958 2,924,484 Tolsma Feb. 9, 1960 FOREIGN PATENTS 554,267 Belgium of 1957 

1. A CONVEYING DEVICE COMPRISING A PLATE, A BRACKET DISPOSED BELOW AND SUBSTANTIALLY PARALLEL TO THE PLATE, A SLEEVE SECURED TO AND MOVABLE WITH THE PLATE AND EXTENDING DOWNWARDLY TOWARD THE BRACKET, A ROD DISPOSED WITHIN THE SLEEVE AND WITH ITS LOWER END SECURED TO THE BRACKET, SAID SLEEVE BEING MOVABLE ON THE ROD, A PAIR OF ADJACENT GRIPPER PLATES CARRIED BY AND EXTENDING DOWNWARDLY FROM THE BRACKET, GRIPPING MEANS FORMED ON THE OUTER FACES OF THE GRIPPER PLATES, A SECOND PAIR OF GRIPPER PLATES WITH ONE FACING END OF THE FIRST PAIR OF GRIPPER PLATES, SAID SECOND PAIR OF GRIPPER PLATES BEING CARRIER BY THE BRACKET AND LINKED TO THE SLEEVE BY A LEVER SYSTEM, A WEDGE DISPOSED BETWEEN THE FIRST PAIR OF GRIPPER PLATES AND CARRIED BY THE SLEEVE, SAID WEDGE SPREADING THE FIRST PAIR OF GRIPPER PLATES CAUSING THEM TO MOVE CLOSER TO THE SECOND PAIR OF GRIPPER PLATES IN RESPONSE TO UPWARD MOVEMENT OF THE SLEEVE ON THE ROD, MEANS SECURED TO THE PLATE FOR RAISING AND LOWERING THE PLATE AND THE SLEEVE RELATIVE TO THE ROD, AND MEANS FOR LOCKING THE ROD AND SLEEVE TOGETHER AND MEANS INCLUDING A FEELER DEPENDING DOWNWARDLY FROM THE LOWERMOST PORTION OF SAID GRIPPING PLATES FOR PREVENTING THE BRACKET AND GRIPPERS FROM ENGAGING THE ARTICLE TO BE CONVEYED BY THE DEVICE AND A SURFACE LYING BELOW SAID ARTICLES. 